Farsighted Spectrum Resource Assignment Method for Advance Reservation Requests in Elastic Optical Networks

Elastic optical networking is a promising technology for the future optical core networks and advance reservation (AR) applications are rapidly increasing in recent years. Hence, the routing, modulation and spectrum assignment (RMSA) problem for AR requests in elastic optical networks (EONs) has become an important issue. In this paper we will investigate the problem. We introduce a metric to measure the situation of each available frequency-time block for an AR request. The metric is the weighted sum of four factors, namely resources consumed by the block (<inline-formula> <tex-math notation="LaTeX">$R_{c}$ </tex-math></inline-formula>), distance between the block and the frequency boundary (<inline-formula> <tex-math notation="LaTeX">$D_{f}$ </tex-math></inline-formula>), distance between the block and the earliest starting time of AR request (<inline-formula> <tex-math notation="LaTeX">$D_{t}$ </tex-math></inline-formula>), and resource degraded by the block (<inline-formula> <tex-math notation="LaTeX">$R_{d}$ </tex-math></inline-formula>). Then we design an RMSA algorithm named Min-RDDR to select spectrum resource for AR requests by minimizing the metric. Simulation results show that the Min-RDDR algorithm has a lower blocking probability, comparing with three well-performed benchmark algorithms.